For "intermodal transport", sometimes referred to as roadway containerized shipping, a longitudinally extending cargo-carrying container is superimposed in immediately overlying condition with and removably attached to a drayable (e.g. tractor-drawn) wheeled chassis.
For the drayable chassis, typically there are transversely aligned front-lock stations and also transversely aligned rear-lock stations. The cargo-carrying container, along a horizontal flooring thereof, extends for a fixed nominal container-length from a forward-end to rearward-end thereof. At the two frontal/lower corners of the container, there are transversely aligned frontal-end fixtures (aka "castings") which are removably engageable with the drayable chassis front-locks (or equivalent means). And at the two rear/lower corners of the container, there are rearward-end fixtures (aka "castings") which are customarily removably engaged at the drayable chassis rear-lock stations.
For a relatively lengthy cargo-carrying container of some selected nominal container-length (e.g. 45-feet, 48-feet, 53-feet), it has been deemed axiomatic by prior art workers that the same nominal container-length must also exist between the front-lock means and the rear-lock stations of its underlying drayable chassis. Accordingly, toward the objective of accommodating more than one nominal container-length, prior art workers have provided drayable chassis of adjustable longitudinal length so that the distance between the front-lock means and the rear-lock stations will substantially equal the end-to-end container-length. However, such adjustable length type drayable chassis are excessively weighty, expensive, cumbersome, and difficult to adjustably alter. Moreover, in prior art, when attaching the rear-ward ends of the chassis and overlying container, it is impossible to accommodate different length containers on a single chassis having a fixed wheeled axle setting and maintain a constant setting between the chassis kingpin and wheeled axle.